Astron. Astrophys. Suppl. Ser.
Volume 136, Number 2, April II 1999
|Page(s)||363 - 372|
|Published online||15 April 1999|
The nature of the star clusters ESO 93-SC08 and ESO 452-SC11 *
Universidade Federal do Rio Grande do Sul, Dept. de Astronomia, CP 15051, Porto Alegre 91500-970, Brazil
2 Università di Padova, Dept. di Astronomia, Vicolo dell'Osservatorio 5, I-35122 Padova, Italy
3 Universidade de São Paulo, CP 3386, São Paulo 01060-970, Brazil
Accepted: February 1999
We present V and I colour-magnitude diagrams of the star clusters ESO 93-SC08 and ESO 452-SC11. Both clusters are poorly populated, and the colour-magnitude diagrams show that ESO 93-SC08 is an intermediate age open cluster, while ESO 452-SC11 is confirmed as a globular cluster. The magnitude difference between the turnoff and the clump/horizontal branch indicates an age of Gyr for ESO 93–SC08, while ESO 452–SC11 has an age comparable to the average of the halo globular clusters. ESO 93–SC08 has a reddening of = 0.64 and is located at kpc from the Sun. It is a distant open cluster in the outer disk. ESO 452–SC11 appears to be a southern counterpart of the Palomar clusters. We derive a reddening of , a distance kpc and a metallicity Fe/H ≈ -1.5 for ESO 452–SC08. The deep CMD shows evidence of depletion at the lower main sequence, similarly to other poorly populated globular clusters.
Key words: globular clusters: ESO 452–SC11, open clusters: ESO 93–SC08 / HR diagram
© European Southern Observatory (ESO), 1999